fileexpressionstore.java

一个工作流设计及定义的系统,可以直接与数据库结合进行系统工作流程的定义及应用.

/*
 * Copyright (c) 2005, John Mettraux, OpenWFE.org
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * 
 * . Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.  
 * 
 * . Redistributions in binary form must reproduce the above copyright notice, 
 *   this list of conditions and the following disclaimer in the documentation 
 *   and/or other materials provided with the distribution.
 * 
 * . Neither the name of the "OpenWFE" nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * $Id: FileExpressionStore.java,v 1.25 2005/07/17 16:31:49 jmettraux Exp $
 */

//
// FileExpressionStore.java
//
// [e-mail]
//
// generated with 
// jtmpl 1.0.04 20.11.2001 John Mettraux ([e-mail])
//

package openwfe.org.engine.impl.expool;

import openwfe.org.Utils;
import openwfe.org.ApplicationContext;
import openwfe.org.ServiceException;
import openwfe.org.xml.XmlUtils;
import openwfe.org.time.Time;
import openwfe.org.misc.DirectoryFilter;
import openwfe.org.engine.expool.PoolException;
import openwfe.org.engine.expressions.UrExpressionId;
import openwfe.org.engine.expressions.ReplyException;
import openwfe.org.engine.expressions.FlowExpression;
import openwfe.org.engine.expressions.FlowExpressionId;
import openwfe.org.engine.expressions.ExpressionWithTimeOut;


/**
 * Half an implementation of an expression store
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Date: 2005/07/17 16:31:49 $
 * <br>$Id: FileExpressionStore.java,v 1.25 2005/07/17 16:31:49 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public abstract class FileExpressionStore

    extends AbstractExpressionStore

{

    private final static org.apache.log4j.Logger log = org.apache.log4j.Logger
        .getLogger(FileExpressionStore.class.getName());

    //
    // CONSTANTS (definitions)

    /**
     * Use this parameter to indicate to a FileExpressionStore in which 
     * directory it should save its run data.
     */
    public static String P_WORK_DIRECTORY 
        = "workDirectory";

    //
    // FIELDS

    private String workDirectory = null;
    private String urExpressionPath = null;

    //
    // CONSTRUCTORS

    public void init 
        (final String serviceName, 
         final ApplicationContext context, 
         final java.util.Map serviceParams)
    throws 
        ServiceException
    {
        super.init(serviceName, context, serviceParams);

        //
        // determine workDirectory

        this.workDirectory = (String)serviceParams.get(P_WORK_DIRECTORY);

        this.workDirectory = Utils.getCanonicalPath
            (getContext().getApplicationDirectory(),
             this.workDirectory);

        this.workDirectory += java.io.File.separator;

        this.urExpressionPath = this.workDirectory + "ur-expression.xml";

        log.info("init() workDirectory set to "+this.workDirectory);
    }

    //
    // ABSTRACT METHODS

    protected abstract void saveExpression (String fileName, FlowExpression fe)
        throws Exception;

    protected abstract FlowExpression loadExpression (String fileName)
        throws Exception;

    //
    // METHODS

    /**
     * Stores an expression to a file in the pool directory.
     */
    public void storeExpression (final FlowExpression fe)
        throws PoolException
    {
        log.debug("storeExpression() for "+fe.getId());

        final long start = System.currentTimeMillis();

        final Object monitor = getMonitorMap().getMonitor(fe.getId());

        synchronized (monitor)
        {
            //log.debug
            //    ("storeExpression() entering >>> "+start+
            //     " h"+fe.getId().hashCode());

            try
            {
                //
                // does WFD directory exist ?
                
                final java.io.File dir = 
                    new java.io.File(determineDirName(fe.getId()));

                if ( ! dir.exists()) dir.mkdirs();

                //
                // store expression

                final String fileName = determineFileName(fe.getId());

                // some debug output (remove it when delete() problem is solved)
                //
                //if ((new java.io.File(fileName)).exists())
                //{
                //    log.debug
                //        ("storeExpression() "+fileName+" already exists.");
                //}

                saveExpression(fileName, fe);
            }
            catch (final Exception e)
            {
                throw new PoolException
                    ("Failed to store expression", e);
            }

            //log.debug
            //    ("storeExpression() leaving  <<< "+start+
            //     " h"+fe.getId().hashCode());
        }

        final long duration = System.currentTimeMillis() - start;
        log.debug("storeExpression() took "+duration+" ms");
    }

    /**
     * Removes an expression (deletes its file) from the pool directory.
     */
    public void unstoreExpression (final FlowExpression fe)
        throws PoolException
    {
        String fileName = determineFileName(fe.getId());

        log.debug("unstoreExpression() deleting file "+fileName);

        java.io.File f = new java.io.File(fileName);

        boolean result = f.delete();

        if (result == false) log.debug("unstoreExpression() delete failed");

        log.debug("unstoreExpression() unstored "+fe.getId());

        if (fe.getParent() == null)
        {
            final String dirName = determineDirName(fe.getId());
            final java.io.File dir = new java.io.File(dirName);

            dir.delete();

            log.debug("unstoreExpression() removed dir "+dir.getPath());
        }
    }

    /**
     * Loads (deserializes) an expression from the pool directory.
     */
    public FlowExpression loadExpression (final FlowExpressionId fei)
        throws PoolException
    {
        log.debug("loadExpression() requested for "+fei);

        long start = System.currentTimeMillis();

        String fileName = determineFileName(fei);

        log.debug("loadExpression() fileName is "+fileName);

        FlowExpression result = null;
        try
        {
            result = loadExpression(fileName);

            //result.setApplicationContext(this.applicationContext);
        }
        catch (final Exception e)
        {
            //log.debug
            //    ("Failed to load expression", e);
            throw new PoolException
                ("Failed to load expression", e);
        }

        long duration = System.currentTimeMillis() - start;
        log.debug("loadExpression() took "+duration+" ms");

        return result;
    }

    //
    // file name determination

    private String getLastDigit (final FlowExpressionId fei)
    {
        final String wfid = fei.getParentWorkflowInstanceId();

        return wfid.substring(wfid.length()-1);
    }

    /**
     * Determines in which dir an expression should be stored.
     */
    protected String determineDirName (final FlowExpressionId fei)
    {
        //log.debug("determineDirName() fei is "+fei);

        if (UrExpressionId.UR_EXPRESSION_ID.equals(fei))
            return this.workDirectory;

        StringBuffer sb = new StringBuffer();

        sb.append(this.workDirectory);

        sb.append(Utils.ensureForFileName(fei.getWorkflowDefinitionName()));
        sb.append("--");
        sb.append(Utils.ensureForFileName(fei.getWorkflowDefinitionRevision()));

        sb.append(java.io.File.separator);

        sb.append(getLastDigit(fei));

        sb.append(java.io.File.separator);

        sb.append(fei.getParentWorkflowInstanceId());

        sb.append(java.io.File.separator);

        return sb.toString();
    }

    /**
     * Determines under which filename an expression should be stored.
     * It returns a full (absolute) path.
     */
    protected String determineFileName (final FlowExpressionId fei)
    {
        if (UrExpressionId.UR_EXPRESSION_ID.equals(fei))
            return this.urExpressionPath;

        StringBuffer sb = new StringBuffer();

        sb.append(determineDirName(fei));

        sb.append(Utils.ensureForFileName(fei.getInitialEngineId()));
        sb.append("--");
        sb.append(fei.getWorkflowInstanceId());
        sb.append("--");
        sb.append(fei.getExpressionName());
        sb.append("--");
        sb.append(fei.getExpressionId());
        sb.append(".xml");

        return sb.toString();
    }

    /**
     * This method returns an iterator on all the expression stored here
     * whose class is assignable from the given 'assignClass'.
     * This method is used by daemons checking the content of the store for
     * purge and timeout purposes.
     */
    public java.util.Iterator contentIterator
        (final Class assignClass)
    {
        final long startTime = System.currentTimeMillis();

        final String[] shortNames = determineExpressionShortNames(assignClass);

        final java.util.List result = new java.util.ArrayList();

        //
        // roam through every directory